Electric cooking plate



May 21, 1929.

R. H. MaclNNEs ELECTRIC COOKING 'PLATE File'd Aug. 29, 1927 2 sheets-'sheet 1 May 21, 1929.

R. H. Mmmm-:s 1,714,175

ELECTRIC COOKING .PLATE Filed -Aug. v 29. 1927 v 2 Sheets-Sheet 2 ,gopgrid-plate pro er removed and Patented May.l 21, 1929.

UNITED STATES PATENT OFFICE.

v ROBERT H. KACINNES, OF CHICAGO, ILLINOIS, ASSIGNOR TO CRIBBEN & SEXTON l COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ELEc'rnIc cooxnm Harn.

Appiication mea August 2a, 19a?. serial mjmaias.

This invention relates to an electric cook# ing-plate adapted to be employed as a hotplate mounted in the cookin -top of an electric range, or in any suita le supportingplate. The primary object is to provide an improved device of this character vwhich is staunch and can be readily assembled.

The invention is illustrated in a referred embodiment in the accomnying rawings, ,in which v Fig. 1 is a broken vertical sectional -view showmg the improved device mounted in a hole, or socket, of,an electric-range topplate, for example; Fig. 2 is a plan view of' the refractory grid-plate proper which is employed; Fig. 3, a broken plan view of the construction shown in Fig. 1, but

leading from t e resistance-coil cut; Fig. 4, a broken planview of the hanger, or stirrup, 'which de ends lfrom the top-plate, orsupporting-grate, and the socket mounted thereon; and ig. 5, a broken bottom view of the heating` unitwhich includes an adapter, a socket-member mounted therein, and the grid-plate proper.

In the construction illustrated, A desig' nates a supportinglate which may constitute, for example, t e topI late of' an electric-range; B, a hanger epending from said plate; C, a socket with which the hanger, orxstirrup B is equipped; D, an ada ter mounted in a hole, or socket, A', with w ich the supporting-plate A is provided; D', a socket-member carried by the adapter D and ixedly secured thereto; D2 a grid-plate properF mounted in theJ adapter above the 4 0 member D; and E, an electric heating element, or resistance-coil, mounted in the member D2. v

The supporting-plate A is shown provided on opposite sides of the socket A withl depending lugs 1 over which it the perforations 2 with which the end-portions of the stirrup B are provided. A clip 3 servesto secure the parts together.- This clip issecured tothe plate A by screws 4 connected v with tapped openings in the lugs 1. Thev clip Shas upturned flanges 3a which support the flanges of the stirrup B.

The stirrup B has a web-portion 5 spaced a considerable distance below the plane of durable and the parts of which with the the wires.

member 7 and extending through perfora-v tions inthe base of the disk, or block, 6; a central spring contact 9 disposed in a recess 10 extending below the main socket-member 7 ,the contact 9 being in the form of a ,resilient strip-bent into U-formand being secured in the socket 10,by a bolt 11 which extends through a central perforation in the base portion of the block 6; and an annular contact-rin 12 mounted in a corresponding recess int e upper portion of the block 6 vand secured in positlon by bolts 12* which 'extend through perforations in the block 6.

The block 6 has its base provided with a reduced portion 6b which extends freely through the perforation 5 of the stirrup. Clips 13 secured to the upper side of the web 5 of the stirrup b means of screws 13IL serve to preveift dislo gment-of the block 6, it being noted that the clips 13 are provided with inturned flanges 13b which extend over the flange 6 ofthe insulation-block.

Wires a,`b and c are connected, respectively, with one of the bolts 12a, one of the bolts 8, and the central bolt 11. These wires fmay be connected with line wires through the medium of suitable switches (not shown), and thus the'energizing-circuit may be connected with the contact-ring 12, the

`socketmember 7, and the central contact 9,

in any desired manner.

The ada ter D preferablyv is in the form of a dished) annular member which ma be of cast-metal. It affords 'a shell in w ich` the 'sgcket-member D and the grid-plate, D2 are mounted. The adapter is provided at its uper portion with an annular flange 14 whic rests in the socket A. The adapter has an annular` stepped form, 'which provides an internal shoulder 14 adapted to support the grid-plate, and a bottom portion 14b adapted to support the socket D. The adapter is provided also with a central perforation 14c through which the socketmember D ,protrudes Also, the adapter is is equipped withilugs 15b which are secured to the bottom 14b by means of bolts 16.

Thebody-portion 15 of the socket-member D' is provided with a central depending portion 15V which has secured thereon a spirally corrugated'contact-sleeve 15d which is adapted to screw into the member 7. The body 15 is Jprovided with a bottom surface 15e having an annular recess in which inset a contact-ring 15f. The ring 15 1s secured to the lbody 15 by means of bolts 16 extending therethrough. The contact-member 15d may be screwed onto the projecting portion 15. vertically through the body 15 and connect an inturned flange on the lower end of the member 15d to thebody-portion. The upper ends of the bolts 17 are shown equipped with nuts located in sockets 18 which are provided in an upward extension 18a of the body 15.

A central bolt 19 extends through the body 15 and is provided at its lower-end with a contact-head1?. Wires a', b and c extend through vertical perforations with which the body.15 is provided and connect with the lower ends of the bolts 16, 17 and 19. Thus, these wires are adapted to be placed in circuit respectively with the wires a, b and a `of the socket-member C which is mounted on the stirrup B. The wire a', is shown interposed between the contact-ring 15t and a washer 20 placed on one of the bolts 16.

The grid-plate D2 is pressed, or molded, frpm insulation material of refractory character. "The plate is providedlin its upper portion with suitably curved grooves 21 which are open at their upper sides. Y At the bottom of these grooves are narrower grooves 21u which are crossed at intervals by walls 21". Vertical perfovrations 22 extend from the lower surface of the grid-plate and intersect the grooves 21.

The grooves 21 are struck on arcs from the axis of the grid-plate and are suitably connected at their ends by reversal grooves 23 which enable the resistance-coil to be wound back and forth in a generalmanner known in the art. The inner'walls of the grooves 21 are provided at intervals with overhanging lips 24 which are beveled on their under sides as indicated at 24a in Fig. 1. The opposite or outer wall of the groove is outwardly sloping somewhat as indicated at 25. This arrangement permits the resistance-coil Preferably, bolts 17 extend' to be inserted into the lgroove quite readily, and the lip 24 serves as a retainer, preventing dislodgment of the resistance coil. The construction described renders it unnecessary to notch the ridges between the grooves for the purpose of enabling the resistance-coil to be slipped under or past the retainer-lip.

The wires a, b and c mentioned above extend through perforations with which the grid-plate is provided and connect with the resistance-coil at the points a2, b2 and c2. It will be noted that the wirec is a double wire, corresponding with a loop in the resistance-coil. By means of suitable switches, any one of three different heats may be imparted to the grid-plate. Thus, the portions of the resistance-coil may operate in parallel, in series, or a single portion of the coil may be used. Such a method of operating nthe resistance-coil is known in the art.

It will be noted that th arrangement of the grid-plate D2 with reference to the socket-member D is such as to provide anintervening space F. This enables the wires to be taken from the grid-plate through the socket-member 15 and also provides an airspace between the socket-member D and the grid-plate.

The grid-plate is provided at its periphery with a notch 26 which is adapted to engage the lug 14d of the adapter D. The gridplate is provided at its lower surface near its periphery with an annular flange 27 which lits within the reduced portion of the adapter D. Also, the grid-plate is provided at its lower surface with a centraLannular rib 28. These ribs serve as reinforcing ribs. The circumferential portion of the gridplate preferably is provided with radial notches 29 in a manner known to thev art.

After the wires a', b and c leading .from the resistance-coil have been passed through the perforations provided therefor in the insulation-body 15 and suitably secured to the co tacts, the central bolt 19 is screwed into a nut 30 located in a central socket 31 with which the grid-plate is provided, andthus the gridplate is secured within the upper portion of the adapter D, where it is clamped against the annular shoulder 14a.

From the description given, it will be understood that electricity may be taken from a suitable source through the wires a, and 0, and thus lead to the contact ring 12, the screw-socket 7, and the central springcontact 9 of the socket-member C. When the burner-unit which comprises the adapter D, the socket D', and the rid-plate D2 are introduced into the hole ofg the supporting-plate A, connections are established by turning the burner-unit about its axis, thus causing the socket-member D to be screwed into the socket-member C. Thus, contacts arc established between the threaded contacts 15d and 7; between the central post 19 and llfx lill? central spring-contact 9; and between the annular contact 12 and the annular contact By forming the members lD and D2 independently, it is possible to mold, or dieress, the parts and to make the connections or the contacts with requisite facility; also,

such-construction provides for better uni-v formity in` the. walls of' the insulation bodies; also, the construction provides for isolating the socket-member D in a measure, from the highly heated grid-plate; also, in case ofbreakage, the expense of replacement is reduced to a minimum; also, the grid-plate itself is mounted with acertain degree of freedom in the upper socket of the vadapter D; and, finally, the socketmember D is secured with the necessary firmness to the adapter to insure proper connections when the threaded plug-portion 15c is screwed into the socket-member 7.

The foregoing detailed description has been. given for clearness of understanding on1y,.and no unnecessary limitations should be understood therefrom, but the appended claims should be construed as broadly as permissible, in view of the prior art.

What I regard as new, and desire to secure by Letters Patent, is:

1. An electric burner comprising in combination,.a supporting plate having an opening therein, an adapter-shell designed to be positioned in the opening in the supporting plate, a central socket-member mounted therein and projecting therethrough and equipped with contacts, a grid-plate supported in theupper portion of said shell, a resistance-coil mounted on said grid-plate, and connecting wires joining said resistancecoil tosaid contacts.

2. -An electric burner comprising a dished lannular adapter-shell havmg a steppedform providin a bottom and an internal shoulder some 'stance above said bottom, a socket-member secured 4to said bottom and having a plug-portion extending through the central opening therein and equipped with contacts, a grid-plate mounted in the upper portion of the adapter and resting on the internal shoulder thereof, a resistancel coil mountedin said grid-plate, wires connecting said resistance-coil with said contacts, and bolt-connections between said socket-member and said grid-plate.

3. An electric burner comprising anadapter-shell and a id-plate mounted therein and equipped with a socket-member having a central contact, a screw-contact, and a ring-contact; and a resistance-coil mounted. in said grid-plate and having wiresleading therefrom and connected with said contacts. l

4. In combination, a supportin -p1ate, a stirrup depending therefrom, a soc et-member mounted on said stirrup and provided sistance-coil mounted in said rid-plate and -1 having wires extending there rom and connected with said second-mentioned contacts.

5. In combination, a supporting-plate provided with a hole and equipped with a hanger having a bottom member provided'with a central opening; a socket-member mounted on said hanger, said socket-member comprising an insulation-body equipped at its upper end with a ring-contact and having a central socket equipped with an annular threaded contact and equipped also with a central contact at the bottom of said socket; and a burner-unit comprising an adapter and a gridilate mounted in said adapter and pro' vide with a plug extending through the adapter, said plug being equipped wit-h contact-members adaptedto engage said rstnamed contact-members when thev burnerunit is screwed into the first-mentioned socket-member.

6. An electric burner comprising a hanger equipped with a socket provided with three contacts, one of which is an annular threaded contact and another of which is a central yielding contact; and a burner-unit comprising an adapterA having mounted therein a grid-plate provided with a plug extending through the central portion of the adapter and equipped with three contacts adapted to engage said irst-mentioned contacts, the contacts bein screwing t e plu into the socket.

7. In combination: a su porting-plate provided with a socket and) equipped with a brought into engagement by depcnding hanger; a socket mounted lon the we portion o said hanger .and equipped with a threaded female contact-member and at a lower lane with a central ,yielding contact-mem er and at a higher plane with a ring contact-member; and a burner-unit comprising an annular adapter-shell, a plug secured in the lower portion of said shell and equipped with contacts registering with said first-named contacts, one of the contacts of said plug being an annular threaded contact adapted to screw into said first-mentioned annular threaded contact, a separately formed grid-plate mounted in the upper portion of said adapterand secured to said plug, a resistance-coil mounted in said grid-plate and wires connecting said coil with the contacts of said plug.

8.In means of the characteset forth, a

supporting-plate equipped with a hanger,

a socket-member mounted on'said hanger and provided with a recess containing an annular threaded-contact and with a smaller recess at the bottom of the first recess and containing a resilient Contact, said socketmember bein equipped at its upper end outside of sai threaded contact with another contact; and -a burner-unit comprising an adapter, a plug secured in thevbottom of said adapter and equipped With a central contactpost-and with other contacts corresponding with the other contacts of said socket-member, and a grid-plate secured to. said post.

9. In means ofthe Icharacter set `forth, a

supporting-plate, a hanger depending therefrom, a socket mounted in said hanger and equipped with contacts; and ahurner-unit comprising an. adapter-shell, a plug secured Iplug and adapter-she l. A 10. An electric burnerjcomprising, a sup.` porting plate, a hanger depending therefrom to the bottoin'portion thereof and equipped .with contacts, a, se aratelyv forme idplate mounted in sai -adaptevshelh wit an intervening space between said ygrid-plate and said plug; a resistance-coil mounted insaid gridplate and vhav-ing wires connected with the `contact-1nembers of said plu and means connecting to ethersaid .gri -platezg and' equipped wit-l1 a socket provided with contacts, and a surmounting burner-unit comprising an adapter having mounted therein a grid-plate provided with a vplug equipped with contacts, said plug being provided with a threaded portion depending through the adapter and adapted to screw into said socket.

ROBERT H. MAOINNES 

